This invention relates to an electrophotographic recording apparatus or system that is suitable for use in copiers, facsimile equipment, printers or combinations thereof.
Electrophotographic data recording is commonly practiced in such applications as the output devices of main frames and personal computers and image duplicating copiers and this has contributed to the availability at low cost of high-quality hard copies. Particularly, in low-speed applications where machines operating at a comparatively slow speed have gained increasing acceptance in the past several years, cassette-type models which contain the developing unit, cleaner and other devices around the photoreceptor in one module are expanding the share of market taking advantage of the ease in their maintenance. However, the cassette-type models have many components to be replaced and even in the case where only the toner need be replenished, other parts such as the photoreceptor drum, the developing unit and the cleaner must also be replaced and this has increased the maintenance cost by at least several times as much as would otherwise be required.
The major parts or components that need frequent maintenance in conventional electrophotographic recording apparatus or systems are summarized below.
(1) The photoreceptor has a comparatively short life and needs frequent replacements by a serviceman. Major causes of its short life include not only deterioration due to exposure and ozone but also soiling, damage and wear due to components disposed around the photoreceptor such as the developing unit, transfer unit (including contact with the transfer medium), stripping fingers and cleaner, as well as sensitivity deterioration caused by those phenomena.
(2) In the heat roller system which is one of the most common methods adopted by the fixing unit, the replenishment of the anti-offset silicone oil, cleaning and, optionally, the replacement of the pressure rollers are necessary.
(3) Cleaning is also necessary to insure that the toner particles flying about will not build up on the recording paper to foul it; and
(4) The replenishment of the spent toner.